16505881 has 16 divisors (see below), whose sum is σ = 19839744. Its totient is φ = 13425984.

The previous prime is 16505837. The next prime is 16505911. The reversal of 16505881 is 18850561.

It is a cyclic number.

It is not a de Polignac number, because 16505881 - 2¹¹ = 16503833 is a prime.

It is a super-2 number, since 2×16505881² = 544888215172322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16505381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24951 + ... + 25603.

It is an arithmetic number, because the mean of its divisors is an integer number (1239984).

Almost surely, 2^16505881 is an apocalyptic number.

It is an amenable number.

16505881 is a deficient number, since it is larger than the sum of its proper divisors (3333863).

16505881 is a wasteful number, since it uses less digits than its factorization.

16505881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840.

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 16505881 is about 4062.7430388840. The cubic root of 16505881 is about 254.6124113090.

The spelling of 16505881 in words is "sixteen million, five hundred five thousand, eight hundred eighty-one".